Three al-Jazeera journalists are being detained in Egypt on suspicion of using unlicensed equipment, broadcasting false news and possessing fake footage, prosecutors say.
Earlier reports suggested the men had been charged, but formal charges have not been laid, the men's lawyers said.
Al-Jazeera said the accusations "do not stand up to scrutiny" and rejected "claims that anyone has 'confessed'".
The Qatar-based broadcaster said the prosecutors' statement was "unusual".
"It looks like a prejudgement on an ongoing investigation," the broadcaster said.
Peter Greste - an Australian ex-BBC correspondent - Canadian Mohammed Fahmy, Cairo bureau chief, and Egyptian producer Baher Mohamed were arrested on 29 December at their hotel in Cairo. They have been in detention ever since.
The statement issued by Egyptian prosecutors said their investigations showed the three men had been intending to gather material and tamper with it in order that al-Jazeera could broadcast "fabricated footage that had nothing to do with reality".
The network had the "objective of distorting Egypt's image abroad, damaging its political standing, and making the international public believe that the unreal footage showed what was happening in Egypt and that the country was witnessing a civil war", the prosecutors alleged.
"This aims to serve the objectives of the international organisation of the terrorist group and provoke the international community against Egypt," they added, apparently referring to the Muslim Brotherhood.
In its statement, Al-Jazeera said: "Our detained team had been working in Cairo for some time and people can still watch their work online.
"It was all of the highest journalistic standards and integrity, as has been all our output since the start of the momentous events in Egypt three years ago."
The broadcaster urged the Egyptian authorities "to take heed" of calls by international media organisations for the release of its journalists.
A letter signed by more than 40 editors and journalists earlier this week appealed for an end to their "arbitrary imprisonment" and said the arrests had "cast a cloud over press and media freedom in Egypt".
The Egyptian authorities have long accused al-Jazeera of bias in favour of the Muslim Brotherhood since the army ousted President Mohammed Morsi in July.
Earlier in December, the Brotherhood was declared a terrorist organisation, amid a crackdown on the group in which hundreds of pro-Morsi protesters have been killed and thousands of Brotherhood supporters arrested.